Sleep and Wakefulness Flashcards
Which stage of sleep has the most intensity of muscle tone?
REM
Which organ has an impact in maintaining sleep/wakefulness?
thalamus
What is wakefulness?
An aspect of quantitative consciousness
Define quantitative consciousness
Full wakefulness, fall easily asleep , need forceful sensory stimuli to be woken up, absence of sopulin/coma
Define qualitative consciousness
Incoherent thinking, delir, hallucinations, delusions
Define state of vigilance
All states of wakefulness and sleep
Define arousal
Transition from sleep to wakefulness
What is a common scale that assesses degree of impaired consciousness?
Glasgow coma scale eg less than 8 pts means assisted ventilation
What did transection of different brainstem parts in classical wakefulness experiments reveal?
Structures involved in wakefulness-between medula oblangata and mesencephalon in the cerebellum
Name 2 subcortical activating systems?
- brainstem: raphae nuclei, LDT, BV (ACh), LC (NA), VTA(dopamin) maintain wakefulness
- hypothalamus: VLPO-GABA sleep inducing, LH-Orexin, TMN-histamin
Monoaminergic nuclei maintain wakefulness. True/false
True
How do monoaminergic nuclei maintain wakefulness?
- Changes within these nuclei imply changes in sleep stages
2. The nuclei have NTs whose changes vary level of alertness ie wakefulness/sleep
Define different frequencise alpha beta theta gamma
gamma-0.5-4Hz
theta-4-8 Hz
alpha- 8-12 Hz
beta- 12-30 Hz
Artefact induced by eye opening/closing indicates
supression of alpha waves
Quantitative measure for recording of sleep disorders
polysomnography- sleep period, breathing, heart beat, movements in sleep
Deficiency in orexin leads to which disorder?
Narcolepsy
Duration of an epoch
30 seconds
Disappearance of alpha EEG means
transition from wakefulness to superficial sleep
What does hypnagogic theta signify?
Person is going to sleep (4 to 8 Hz)
What is a sleep related breathing disorder?
Cheyne-stokes breathing/ apnea/hypopnea
What is a characteristic of a pathological hypnogram?
Longer duration of slow wave sleep, 18 awakenings
Example of REM exclusive sleep body disorder
Narcolepsy
Define REM sleep muscle atonia
patients lose muscle tone, collapse,though brain is awake dissociation of 2 states of vigilance
What is a defining symptom in narcolepsy
cataplectic attack strong emotion/laughter causes a person to suffer sudden physical collapse though remaining conscious.
Define pure nacolepsy
individuals who fall asleep from one moment to the next, unspecific, excessive daytime sleepiness
cataplexy
Name some REM wake dissociations
Sleep paralysis-motor system lags behind in process of awakening
Hypnagogic hallucination -parts of the brain are still dreaming but brain is awake
REM preceeds NREM sleep in narcolepsy. True/false
True
Sleep test exmaple
Multiple sleep latency test- put people to sleep several times in a day
Duration of one sleep cycle
90 to 120 minutes
NT produced in the lateral hypothalamus
orexin. Shows different affinity to receptors hypocretin 1 and 2
Which NT plays a role in the nuclei that synchronize subcortical activating systems
Orexin
